SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bcd0095f43fd15f4042461be8343fb7fd49a8fdd9564f2f8f3343526fded44a' 
  AND token = '7fW8HurFahw1O9lOUXHLJkfb6H0YsWsfSr3+VEYZO04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}